Download Introduction to Tympanometry

Introduction to Tympanometry
Chris Patricoski MD FAAFP
Definition
• Tympanometry measures the compliance
of the TM and ossicular chain and
estimates middle ear pressure.
• Compliance = Freedom of Movement (cc)
Anatomy of the Ear
Anatomy of the Ear
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External Ear
Middle Ear
Inner Ear
Pinna
Auditory Canal
Tympanic Membrane
Ossicular Chain
• Malleus
• Incus
• Spapes
Stapedial Muscle
Oval Window
Cochlea
External Anatomical Landmarks
of the Ear
Hearing
• Sound energy stimulates the TM
(eardrum) vibrating the ossicular chain.
Vibratory motion of the stapes is
transmitted through the oval window into
the cochlea.
• Cochlea translates the sound energy into
meaningful neuronal impulses to the brain.
Cranial Nerve VIII
How it Works
Tympanometry utilizes two energy sources:
• Pressure
• Sound
Units:
1. Pressure = daPa (deca Pascals)
2. Sound = Hz (Frequency) dB (Loudness)
3. Compliance = cc
How it Works
• Pressure is
introduced from +200
to – 300
• Sound is constant at
226 Hz and 85 dB
• Compliance is
measured in terms of
volume (cc)
How it Works
• Pressure changes on
the x-axis (horizontal)
• Compliance changes
on the y-axis (vertical)
Values
Values
Clinical Indications
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Nonspecific ear complaints
Hearing Loss
Ear pain without observed problems
Subtle TM changes
Middle ear effusion; Serous Otitis
Resolved Otitis Media
Ear Tubes
Screening
Normal Ear
Otitis Media
Tympanostomy Tube - Functional
Compliance of the TM & Ossicles
Flat TM: Serous Otitis
Flat TM: Patent Tube
Normal
Abnormal: Negative Pressure
Abnormal: Negative Pressure Wide
GR, maybe air pockets in mid ear
Abnormal: Hyperflaccid TM